Type of Operators

Hi @milad.showkatbakhsh and @mmakki_10

I am wondering which crossover operator (Uniform, SBX, SPX) Wallacei uses?
Also, would it be possible to change the crossover operators in Wallacei?


Hello Nariman,

The public release of Wallacei uses SBX Crossover, (the hyperparameter “Distribution index” in the UI corresponds to that).

Thanks, Milad. That’s great. And can you explain the relationship between the distribution index and different types of crossover? Also, I think you mean the value of 20 for the distribution index is representing the type of SBX in Crossover, right?

Many thanks,

The public release of Wallacei uses SBX Crossover. this operator has a multiple important hyperparameters two of which that are exposed in the UI are Distribution Index and Cross Over probability. As for the Distribution Index, It controls the shape of the probability distribution used in the crossover in the other words, it determines the balance between exploration and exploitation. A higher value results in a more uniform distribution, promoting more exploration and generating diverse set of offspring. On the other hand, a lower value concentrates the distribution around the parent solution, promoting more exploitation and producing offspring closer to the parent solutions. The Crossover Probability determines the likelihood of applying the SBX crossover to a pair of parent solutions. It is usually a value between 0 and 1. A high crossover probability ensures that crossover is applied frequently, promoting exploration and diversity. in the other hand, a low crossover probability makes the crossover being applied less often, favouring more exploitation and maintaining the existing solutions.
hope it helps.